Hydrochlorothiazide / methyldopa Pregnancy Warnings

Animal studies have failed to reveal evidence of fetal harm. In humans, treatment with methyldopa has revealed improved fetal outcome as well as reduced infant average head circumference (0.4 cm). There are no controlled data in the first trimester of human pregnancy; there are no controlled data for hydrochlorothiazide in the second and third trimesters.

US FDA pregnancy category C: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.

Comments: According to some experts, the individual components of this drug can be used safely during lactation; hydrochlorothiazide 50 mg per day or less is considered acceptable during lactation while no special precautions are required for methyldopa.